Inboard Diesels

Juspalm · 04 January 2004, 07:40

I have been running an inboard diesel rib for three years now and have had great fun, fishing, cruising, taking photos, wakeboarding, donuting, (yes behind a smelly diesel), better than behind a smelly two stroke! I am running a 5.8 mt rib with a Yanmar 4LHDTE on to a Castoldi 05 Jet. No Major problems (touch wood). I have been looking around to upgrade to something bigger and have noticed, several 7mt ribs by various builders for sale, running the new Mercruiser 120hp diesel. This engine has only been available for a year or two and I haven't heard any comments about it at all. Has anyone had any experiences of these engines, good or bad,they would like to share. I am a bit concerned as there does seem to be rather alot of them for sale at the moment. Are they under powered? Are they uneconomical? Are they expensive on spares or servicing? Thanks in advance and if anyone is interested in a small diesel jet drive let me know.
justin@pclimited.freeserve.co.uk

Jono Garton · 04 January 2004, 09:47

Hi

I am supposed to have the 120hp merc coming in a 6.5m Prosport. But considering upgarding to the new volvo D3????

nik · 04 January 2004, 14:23

Hi Juspalm,
I too have been looking for diesel ribs and was quite interested by the mercruiser 120d. I have heard both good and bad reports about it, although nothing specific. I believe it is a marinised astra engine. But what is putting me off is that I am not convinced that it is powerful enough.
What does interest me more is the Steyr diesel engine. It is a 2133cc engine that comes in 3 flavours 2@ 144 hp & 1@164 hp. And it is about the same size and weight as the mercruiser. They come in at around £12k, which I think is more than the mercruiser.
The volvo kad32dp is also interesting because it has a supercharger. But it is a bit bigger, heavier, and more expensive. Also some people dont seem to rate volvo after sales.
I must say though I have only seen these engines on stands, I have not seen them in action.
Hope this helps, Nick.

Petrov · 04 January 2004, 15:28

I have been driving a lot of Steyr (212 and the 246) and i just love them, it`s a very reliable engine.
The only problem we have here in Sweden is that there is very few places to get parts, service etc.
Before buying i have to recomend you to check around were you have your boat that there is a service station.
One good thing to here from a guy in Sweden (service station) is that it`s hard to sell them because you never have any engines that brakes down so they get some work on the engines, they only earn money of selling the engines and service, no other jobs.
Good commercial for the engines but the problems comes to find a service station.
No coments of the Volvo, i am swedish so you know what i say, buy it

Daniel · 04 January 2004, 15:59

Andre has one in his Parker and is pleased with it. He has commented here before how ideal it is for a 6-6.5mtr boat but prob not big enough for anything bigger.

I know a guy with one in a 6.5m Humber which he is very pleased with and i was impressed with the top speed. His quoted economy was exceptional as well.

I beleive Mike C also has this engine in his 6.5ish mtr Humber.

Of these three i don't know of any problems, and i think we would have heard if there had been.

simmons0 · 04 January 2004, 16:22

Mike C had a small problem but that was due to poor installation by Humber

Also humber claim top speeds of 46 knots in a 6m ocean pro.
Bull*hit in my opinion but id like to ask andy roffee about it.

Jono Garton · 04 January 2004, 17:11

WHERE AND WHEN DID HUMBER SAY 46KNOTS?

Juspalm · 04 January 2004, 17:49

Thanks Guys it's all helping !! I have heard of a small percentage of engine being hard to start? anyone heard this?

Andre · 04 January 2004, 18:30

Quote:

Originally posted by Juspalm
Thanks Guys it's all helping !! I have heard of a small percentage of engine being hard to start? anyone heard this?

If you mean the Mercruiser 1.7L TDI then this is rubbish - no starting problems . I have done about 187 hours and have not experienced such problems or any problems. Do a search on this engine and you will find a few threads refering it.
From memory no negative opinions.

I would highly recommend it for a 6-6.5 mtr rib

Andre

Chris Murray · 04 January 2004, 19:37

Hi Juspalm,

If you are running a 170hp diesel now in a 5.85, why on earth do you want to consider a 120hp in a 7 metre boat?

I imagine that the relatively more comfortable ride in a bigger boat will make it seem slower than your current one, even if the top speed is identical (which is very unlikely).

I should have thought that the loss of performance is likely to make the whole experience less fun!

Regards,

Chris.

nik · 04 January 2004, 19:38

If you have a hard to start diesel (boat or car) then:
you have a clapped starter motor, clapped battery, or a clapped engine.
Otherwise it should be first go`ish, apart from no fuel or really really really cold conditions (sub arctic).
nick

simmons0 · 04 January 2004, 22:34

Quote:

WHERE AND WHEN DID HUMBER SAY 46KNOTS?

Jono - Ive just found the article, its from 'Divemagazine' and was given to me along with hundreds of other magazine articles by Humber.

They have a test of a 6.3m Humber ocean Pro and claim that it does 45 knots with a 25in pitch prop.

I dont believe it at all but it'd be interesting to see how Mike C's boat did with a 25 inch prop.

seafariskye · 04 January 2004, 23:59

Quote:

The volvo kad32dp is also interesting because it has a supercharger. But it is a bit bigger, heavier, and more expensive.

I disagree -- the fact that the whole KAD range is different, interesting is the fact that they all have compressors on them...
This gives, by far an enhanced much more power -- low end of the revs range, and is invaluable for heavy loads, getting out of tricky situation in a hurry.
the supercharger is an added bonus -- my 7m with a kad 32 in it can easily get going to a happy easy cruising speed with 14 people in it... thats where the volvos are a1.
after sales ... choose carefully where you buy it from, i have had no problems.
45 knots with the mercruiser in a 6m -- Cach ( gaelic For Sh*t)

Has no-one had any experience with the new VW inboards?? they look great ???

Pete F

Garygee · 05 January 2004, 09:36

Hi folks

The 120HP was one engine I looked at in a Humber before I bought Ribcraft.

Went for a spin in it at Rixed 2001, in their new 6.3M (extra wet) Extream RIB. This was compaired with their 7M with a 150HP outboard on the same day.

I thought the 7.0 with the 150HP outboard peformance was OK but the 120HP in the 6.3 was marginal and that was with it being run flat out, with little fuel & 3 adults onboard.

Out of the two the 150HP was faster. I didnt have a GPS on me but the 120HP did not feel like 45Kts, more like 35Kts

I wanted Humber to quote on the KAD32 in the 7.0 but they refused.
In my opinion the 120HP is OK in 6.0/6.5M class boat when loaded light, but would not be sure about anything bigger. A lot depends on how easy the hull is to drive & the useage.

For offshore I would not like to have to run flatout all the time with nothing in reserve.

I know that Ribcraft recomended at least the KAD32 in their 6.8M

I ended up with a 7.8 with 240HP Yanmar, but have always thought the 120HP would be a interesting twin installation for somthing this size.

The new ranges of small compact diesels are looking good, but have no track recod at present.

Regards Gary

Juspalm · 05 January 2004, 12:47

Thanks I'm finding all very helpfull

Daniel · 05 January 2004, 12:52

Quote:

Originally posted by Chris Murray
If you are running a 170hp diesel now in a 5.85, why on earth do you want to consider a 120hp in a 7 metre boat?

It's a jet drive. Although i have no experience of these, i beleive they are quite inefficient and, although i am purely guessing here, would this not be more like a 120hp on a prop drive? In which case getting a bit bigger boat (6.3 / 6.5) would be OKay.

IMHO (with little experience, just listening to what people are saying) 7mtr is too big for the 1.7li 120hp Mercruiser. A 7mtr boat is also HUGE to tow, even behind a Range Rover or something, which is why i went for a 6mtr boat in the end infact, worth considereing.

As far as i know Andre is yet to know if you can ski behind his boat, wort considering from what you initially said.

RIBex might me a good opportunity for you, how about contacting all teh manufacturers and seeing what they'll have with a smelly old diesel in there?

jwalker · 05 January 2004, 13:02

Remember, your outboard will have it's HP quoted at the prop. The diesel wont. It's 112hp at the prop.

Just a bit of info for you. Fitting 2 of these was a very seriously considered option for me. I eventually didn't go that route, partly because the engines are relatively wide and they would need to be shoe-horned in. Wider, if fact, than my single Volvo.

simmons0 · 05 January 2004, 13:05

Quote:

As far as i know Andre is yet to know if you can ski behind his boat, wort considering from what you initially said.

In which case i might take a wetsuit and wakeboard down to trial andre's boat!

Nah, Andres boat will have no problem at all towing a skier. My 5m rib with a 60hp yamaha towed a 16 stone bloke on skis!!!
it was a long pull.....but it did it. Wakeboarding requires even less power.

nik · 05 January 2004, 14:18

Quote:

Originally posted by seafariskye
I disagree -- the fact that the whole KAD range is different, interesting is the fact that they all have compressors on them...

I think you are agreeing with me. The volvo KADs have a supercharger (compressor) as well as a turbocharger.
Therefore giving better low rev response and power.

Nick.

Andre · 05 January 2004, 14:48

Quote:

Originally posted by simmons0
In which case i might take a wetsuit and wakeboard down to trial andre's boat!

Nah, Andres boat will have no problem at all towing a skier. My 5m rib with a 60hp yamaha towed a 16 stone bloke on skis!!!
it was a long pull.....but it did it. Wakeboarding requires even less power.

In an earlier thread started by Georgec this subject was discussed. Georgec came down to Littlehampton but unfortunately Mike C who was going to bring some skis that day was unable to come.

This is however what georgec had to say after his visit:

QUOTE
MeMe your hat is safe.
I was certainly impressed with the brief run which Andre kindly arranged, and following that I finally managed a tug behind a diesel powered rig this weekend. I have to say it is slow in pulling out, and top speed is just sufficent for slaloming ,but the boats weight does compensate as there is no material loss of speed when crossing the wake. The set up was same as Andre's 1.7 mercrusier with 21'' stainless prop.
Not one for serious watersking buffs, but for an old crusier who still fancies the occasional scoot it's a good compromise.
Andre, many thanks for your time the other week, and if you decide on Scotland next summer, get in touch.
UNQUOTE

When I get back from my hols in the sun that is 1 feb I will for sure get my Seahawk back on the water so David/Harry start polishing your skis. Will be in touch.

Andre